//--------------------------------------------------------------------------
// $Id: x08.cc 11760 2011-06-01 19:29:11Z airwin $
//--------------------------------------------------------------------------
//
//--------------------------------------------------------------------------
// Copyright (C) 2004  Andrew Ross <andrewr@coriolis.greenend.org.uk>
// Copyright (C) 2004  Alan W. Irwin
//
// This file is part of PLplot.
//
// PLplot is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; version 2 of the License.
//
// PLplot is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with PLplot; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
//--------------------------------------------------------------------------

#include <plstream.h>

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>

static const char *x_label = "Frequency";

static const char *y_label = "Amplitude (dB)";

static const char *alty_label = "Phase shift (degrees)";

// Short rearranged versions of y_label and alty_label.
static const char *legend_text[2] = {"Amplitude","Phase shift"};

static const char *title_label = "Single Pole Low-Pass Filter";

static const char *line_label = "-20 dB/decade";

class x26 {
public:
    x26( int, const char ** );
    void plot1( int, const char*, const char*, const char*, const char**, const char*, const char* );

private:
    // Class data
    plstream *pls;
};


x26::x26( int argc, const char ** argv )
{
    int i;

    // plplot initialization

    pls = new plstream();

    pls->sdev("psc");
    
    pls->sfnam("out.ps");

    // Initialize PLplot.
    pls->init();
    
    pls->font( 2 );

    plot1( 0, x_label, y_label, alty_label, legend_text,
            title_label, line_label);

    // pls->end();
    delete pls;
}

// Log-linear plot.

void x26::plot1( int type, const char *x_label, const char *y_label,
                 const char *alty_label, const char **legend_text,
                 const char *title_label, const char *line_label )
{
    int        i;
    double      *freql = new double[101];
    double      *ampl  = new double[101];
    double      *phase = new double[101];
    double      f0, freq;
    int32_t      nlegend = 2;
    int32_t      opt_array[2];
    int32_t      text_colors[2];
    int32_t      line_colors[2];
    int32_t      line_styles[2];
    int32_t      line_widths[2];
    int32_t      symbol_numbers[2], symbol_colors[2];
    double      symbol_scales[2];
    const char *symbols[2];
    double      legend_width, legend_height;


    pls->adv( 0 );

    // Set up data for log plot.

    f0 = 1.0;
    for ( i = 0; i <= 100; i++ )
    {
        freql[i] = -2.0 + i / 20.0;
        freq     = pow( 10.0, (double) freql[i] );
        ampl[i]  = 20.0 * log10( 1.0 / sqrt( 1.0 + pow( (double) ( freq / f0 ), 2. ) ) );
        phase[i] = -( 180.0 / M_PI ) * atan( (double) ( freq / f0 ) );
    }

    pls->vpor( 0.15, 0.85, 0.1, 0.9 );
    pls->wind( -2.0, 3.0, -80.0, 0.0 );

    // Try different axis and labelling styles.

    pls->col0( 1 );
    
    pls->box( "bclnst", 0.0, 0, "bnstv", 0.0, 0 );

    // Plot ampl vs freq.

    /*pls->col0( 2 );
    pls->line( 101, freql, ampl );
    
    pls->col0( 2 );
    pls->ptex( 1.6, -30.0, 1.0, -20.0, 0.5, line_label );*/

    // Put labels on.
    pls->col0( 1 );
    pls->mtex( "b", 3.2, 0.5, 0.5, x_label );
    pls->mtex( "t", 2.0, 0.5, 0.5, title_label );
    
    pls->col0( 2 );
    pls->mtex( "l", 5.0, 0.5, 0.5, y_label );

    // For the gridless case, put phase vs freq on same plot.
    pls->col0( 1 );
    pls->wind( -2.0, 3.0, -100.0, 0.0 );
    pls->box( "", 0.0, 0, "cmstv", 30.0, 3 );
    
    pls->col0( 3 );
    pls->line( 101, freql, phase );
    pls->string( 101, freql, phase, "*" );
    
    pls->col0( 3 );
    pls->mtex( "r", 5.0, 0.5, 0.5, alty_label );

    // Draw a legend
    // First legend entry.
    opt_array[0]   = PL_LEGEND_LINE;
    text_colors[0] = 2;
    line_colors[0] = 2;
    line_styles[0] = 1;
    line_widths[0] = 1;
    // note from the above opt_array the first symbol (and box) indices
    // do not have to be specified

    // Second legend entry.
    opt_array[1]      = PL_LEGEND_LINE | PL_LEGEND_SYMBOL;
    text_colors[1]    = 3;
    line_colors[1]    = 3;
    line_styles[1]    = 1;
    line_widths[1]    = 1;
    symbol_colors[1]  = 3;
    symbol_scales[1]  = 1.;
    symbol_numbers[1] = 4;
    symbols[1]        = "*";
    // from the above opt_arrays we can completely ignore everything
    // to do with boxes.

    pls->scol0a( 15, 32, 32, 32, 0.70 );
    pls->legend( &legend_width, &legend_height,
        PL_LEGEND_BACKGROUND | PL_LEGEND_BOUNDING_BOX, 0,
        0.0, 0.0, 0.10, 15,
        1, 1, 0, 0,
        nlegend, opt_array,
        1.0, 1.0, 2.0,
        1., text_colors, (const char **) legend_text,
        NULL, NULL, NULL, NULL,
        line_colors, line_styles, line_widths,
        symbol_colors, symbol_scales, symbol_numbers,
        (const char **) symbols );

    delete[] freql;
    delete[] ampl;
    delete[] phase;
}


int main( int argc, const char ** argv )
{
    x26 *x = new x26( argc, argv );

    delete x;
}
